Executive Summary: Evolution of policies that guide operation of individual reservoir systems begins with a relative flurry of activity associated with building of dams. Over perhaps a ten year period, operations are proposed in anticipation of construction, implemented when a dam is complete, and then modified as the effects, capabilities, and limitations of the project become better understood. After these initial adjustments, the policy process slowly begins to simmer. Operational changes are the driven by short-term influences that are largely episodic (e.g. droughts and floods) and long-term influences (e.g. social and economic factors) that affect operations more gradually.